I have another question : what data are they comparing faces to and how did they get it ? If they are using criminal data from police databases, how did they get the authorization for that,
So probably a decade ago, I was in an employer's security office and looking at their version of this kind of system. Pretty neat, with motion trackers directing cameras, then system doing the zoom & enhance thing on faces that then routed to a screen for review. It was also supposed to be able to do facial recognition against employee ID photos, but apparently wasn't very reliable.
But that was a decade ago*.
Since then, I've visited plenty of customer sites that required photos to get a visitor's badge. So that genie's been out of it's bottle for a while. So those pics could be one source, another could be if KX security catch someone, then ban them from their property.. Possibly for committing heinous crimes like taking photos in what the miscreant thought was public space.. Which has a certain irony to it. I was also told by a rather zealous Docklands security bod that I could be barred from their estate for smoking** in the wrong place. Along with being 'fined' £50.. which was enterprising, if not entirely legal.
But that's the problem with privatising 'public' spaces, especially if the public is unaware it's private property, and any by-laws that may apply for maximising revenue.
and if not, what's the use of the facial recog in the first place ?
Padding sales people's commission, I suspect.
*And probably a decade before that, there were things like Racal's Talon system, part of London's 'Ring of Steel'.
**Smokers being an easy target. Like the number of sites (hospitals etc) that state it's illegal to smoke anywhere on their property, even though UK law bans it in enclosed spaces. And I guess smokers would show up nicely if IR cameras are used.